I am having a '63 pushbutton 727 rebuilt to back a 413 with a thumpr cam, and I have a stall converter out of a 78 727/360 combo that I had built to 2200-2400 stall that never got used. I can have the input shaft swapped on the pushbutton trans to run this later converter, but was wondering if it would give me much more stall than the stock '63 converter? Also, are the 413's internally or externally balanced? The engine is a factory long block from late 60's/ early 70's.

I can't speak to the big block but I've got a 175k converter (~2,400 stall) in my 360 with Thumpr cam and it's just right for the cam. I could definitely tell a difference between it and the stock 360 unit. I'd bet you'd get every bit of that 2,400 + some.

I should mention, though, that I'm ditching the Thumpr cam. Not due to the way it runs but due to the idle. Too nutso for me...

The Thumpr Cam is supposed to retain good vacuum characteristics while having an aggresive tone, and power curve. Did you have trouble in those areas?

Good vacuum at idle (around 12") just didn't like the excessive shake and vibration from the tight overlap. I wanted the aggressive tone but the Thumpr just took it to the next level! Plus, I run A/C so it just wasn't a good fit for me. Made GREAT midrange power though.